Organic light emitting diode display device and method for operating the same

ABSTRACT

An organic light emitting diode (OLED) display device includes a communication transceiver configured to connect with a terminal; a display including pixels constituted by OLEDs; and a controller configured to receive mirroring image data, which corresponds to a screen displayed on the terminal, through the communication transceiver, control the display to display a mirroring image on an area of the display based on the received mirroring image data, and adjust brightness of the displayed mirroring image based on an average picture level (APL) of the displayed mirroring image.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Application is a Continuation of co-pending U.S. patent applicationSer. No. 16/058,652 filed on Aug. 8, 2018, which claims the prioritybenefit under 35 U.S.C. § 119(a) to Korean Patent Application No.10-2017-0150830 filed in the Republic of Korea on Nov. 13, 2017, all ofwhich are hereby expressly incorporated by reference into the presentapplication.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to an organic light emitting diode (OLED)display device, and more particularly to an OLED display device and amethod for operating the same, capable of preventing an afterimagephenomenon caused by irregular lifespans of elements resulting from thedisplay of a mirroring screen in the OLED display device supporting ascreen mirroring function.

Discussion of the Related Art

Recently, as the use of various smart devices and high-resolution largescreens as well as televisions has increased, the types of displaydevices have been diversified. In particular, a variety of flat paneldisplays (FPDs) have been developed which can further reduce the weightand volume than a so-called cathode ray tube (CRT). Specifically, flatpanel displays, such as liquid crystal displays (LCDs), thin filmtransistor-liquid crystal displays (TFT-LCDs), plasma display panels(PDPs), and electroluminescence devices have attracted attention.

The electroluminescence devices may be classified into an inorganiclight emitting diode and an organic light emitting diode (OLED)according to a material of an emitting layer. The OLED is aself-luminous organic material that emits light by itself by using anelectroluminescence phenomenon that light is emitted when a currentflows through a fluorescent organic compound. The OLED can be driven ata low voltage and can be made light and thin. Additionally, since eachdevice is a luminous type that emits light, light is adjusted bychanging a current flowing through each device. Thus, a backlight is notrequired. An OLED display device implemented with such OLEDs hasadvantages such as a fast response time, high image quality, highluminescent efficiency, an ultra-thin structure, and a wide viewingangle.

Due to the above advantages, the prospect of the OLED display device isbright, and the demand for the OLED display device is increasing.

In the OLED display device, as each of elements emits light, theelements may be varied in use frequency and thus the lifespans of theelements may be varied.

Meanwhile, as a terminal such as a smartphone or a tablet PC isextensively spread, a display device has supported a screen mirroringfunction (for example, Miracast, or the like) of displaying, on adisplay unit, a mirroring image corresponding to a screen which is beingdisplayed on a terminal. In general, the mirroring image may be fixedlydisplayed on a specific region (for example, a right upper end of thedisplay unit) of the display unit. The mirroring image may have a higherfrequency in including a still image, as compared with a broadcastimage. Since an OLED element corresponding to a higher brightness regionof the mirroring image continuously emits high-brightness light, theOLED element may have a lifespan reduced more rapidly than an OLEDelement provided in another region. When the lifespan of the elementcorresponding to the higher brightness region is rapidly reduced, thebrightness of light emitted from the device may be relatively reduced.

Accordingly, the afterimage image is caused on a screen of an OLEDdisplay device due to the brightness difference from an element inanother region and thus a user may feel inconvenient in viewing an imagethrough the OLED display device, thereby serving as a main cause ofdegrading the reliability of a product.

SUMMARY OF THE INVENTION

The present disclosure is to provide an OLED display device capable ofpreventing an afterimage phenomenon caused by the reduction in alifespan of an OLED element in a specific region due to the mirroringimage displayed on the specific region of a display unit as a screenmirroring function is executed.

The present disclosure is to provide an OLED display device capable ofchanging the display state of a mirroring image automatically or throughsimple manipulation.

According to an embodiment of the present disclosure, an organic lightemitting diode (OLED) display device includes a communication unit toconnect with a terminal, a display unit including a pixel including anOLED, and a controller to receive mirroring image data, whichcorresponds to a screen displayed on the terminal, through thecommunication unit, to control the display unit to display a mirroringimage on an area of the display unit based on the received mirroringimage data, and to control the display unit not to display the displayedmirroring image on the area based on an average picture level (APL) ofthe displayed mirroring image.

The controller may acquire an APL of a frame of the mirroring image fromthe mirroring image data, may calculate an APL variation by comparingthe acquired APL with a previously-acquired APL, and may control thedisplay unit not to display the displayed mirroring image, based on thecalculated APL variation.

According to an embodiment, the controller may control the display unitto maintain displaying the mirroring image when the acquired APL is lessthan the reference APL, and may control the display unit not to displaythe displayed mirroring image, based on the APL variation when theacquired APL is equal to or greater than a reference APL.

According to an embodiment, the controller may acquire an APL at apredetermined frame interval of the mirroring image, and may control thedisplay unit not to display the displayed mirroring image, whenmaintaining, for a threshold time, a state that the APL variationbetween the acquired APL and the previously-acquired APL is less than areference variation.

According to an embodiment, the controller may display a broadcastimage, which is received from a broadcast reception unit, on the displayunit, may display the mirroring image by overlaying the mirroring imagewith the area of the broadcast image, and may display an overlaidportion of the broadcast image on the area, by controlling the displayunit not to display the mirroring image displayed on the area.

According to an embodiment, the controller may adjust a transparency ofthe mirroring image, based on a time for maintaining the state that theAPL variation is less than the reference variation.

According to an embodiment, the controller may display a broadcastimage, which is received from a broadcast reception unit, on a firstregion of the display unit, may display the mirroring image on the areawhich is not overlapped with the first region of the display unit, andmay increase a size of the first region and reduces a size of the areaas a time for maintaining the state that the APL variation is less thanthe reference variation is increased.

According to an embodiment, the controller may display a screenprotection image on the area, when the controller controls the displayunit not to display the mirroring image on the area.

According to an embodiment, the controller may periodically acquire anAPL of the mirroring image, may increase a count when an APL variationbetween the acquired APL and the previously-acquired APL is less than areference variation, and may control the display unit not to display thedisplayed mirroring image, when the count arrives at a threshold countor exceeds the threshold count.

When controlling the display unit not to display the displayed mirroringimage, the controller may acquire an APL of the mirroring image at apredetermined frame interval based on the mirroring image data receivedfrom the terminal, and may control the display to display the mirroringimage on the area, based on an APL variation between the acquired APLand the previously-acquired APL.

According to an embodiment, the controller may, when controlling thedisplay unit not to display the displayed mirroring image, control thedisplay unit to display the mirroring image, in response to a wake-upsignal received from the terminal as a state of the terminal is changed.

According to an embodiment, the controller may further display amirroring menu on the display unit, and after controlling the displayunit not to display the displayed mirroring image, may control thedisplay unit to display the mirroring image in response to a selectioninput of the mirroring menu.

According to an embodiment of the present disclosure a method foroperating an OLED display device, includes receiving mirroring imagedata, which corresponds to a screen displayed on a terminal connectedwith the OLED display device, from the terminal, controlling the displayunit to display a mirroring image on an area of the display unit basedon the received mirroring image data, and controlling the display unitnot to display the displayed mirroring image, based on an APL of themirroring image.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description given herein below and the accompanying drawings,which are given by illustration only, and thus are not limitative of thepresent disclosure, and wherein:

FIG. 1 is a block diagram illustrating a configuration of a displaydevice according to an embodiment of the present disclosure.

FIG. 2 is a block diagram illustrating a remote control device accordingto an embodiment of the present disclosure.

FIG. 3 is a view illustrating an actual configuration of a remotecontrol device according to an embodiment of the present disclosure.

FIG. 4 is a view of utilizing a remote control device according to anembodiment of the present disclosure.

FIG. 5 is a view for describing a driving principle of an OLED includedin an OLED display device according to the present disclosure.

FIG. 6 is an equivalent circuit diagram of a pixel to which the OLED ofFIG. 5 is connected, according to an embodiment of the presentdisclosure.

FIG. 7 is a view illustrating a screen mirroring function performedbetween the OLED display device and the terminal.

FIG. 8 is a block diagram schematically illustrating elements foroperations of the OLED display device according to an embodiment of thepresent disclosure.

FIG. 9 is a flowchart illustrating the operation of controlling thedisplay state of the mirroring image by the OLED display deviceaccording to an embodiment of the present disclosure.

FIG. 10 is a flowchart illustrating the operation of the OLED displaydevice illustrated in FIG. 9 in more detail.

FIGS. 11 to 15 are views illustrating various embodiments related to theoperation that the OLED display device changes the state of themirroring image to the non-display state, based on the embodimentsillustrated in FIGS. 9 and 10.

FIGS. 16 and 17 are flowcharts illustrating embodiments of an operationthat the OLED display device changes the non-display state of themirroring image according to the embodiments of FIGS. 10 to 15 to thedisplay state.

FIGS. 18 and 19 are views related to the operation of the OLED displaydevice illustrated in FIGS. 16 to 17.

FIG. 20 is a flowchart illustrating embodiments of an operation that theOLED display device changes the non-display state of the mirroring imageaccording to the embodiments of FIGS. 10 to 15 to the display state.

FIG. 21 is a view related to the operation of the OLED display deviceillustrated in FIG. 20.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments relating to the present disclosure will bedescribed in detail with reference to the accompanying drawings. Thesuffixes “module” and “unit” for components used in the descriptionbelow are assigned or mixed in consideration of easiness in writing thespecification and do not have distinctive meanings or roles bythemselves.

A display device according to an embodiment of the present disclosure,for example, as an intelligent display device that adds a computersupporting function to a broadcast receiving function, can have aneasy-to-use interface such as a writing input device, a touch screen, ora spatial remote control device as an internet function is added whilefulfilling the broadcast receiving function. Then, with the support of awired or wireless internet function, it is possible to perform ane-mail, web browsing, banking, or game function in access to internetand computers. In order for such various functions, standardized generalpurpose OS can be used.

Accordingly, since various applications are freely added or deleted on ageneral purpose OS kernel, a display device described in this presentdisclosure, for example, can perform various user-friendly functions.The display device, in more detail, can be network TV, HBBTV, smart TV,LED TV, OLED TV, and so on and in some cases, can be applied to asmartphone.

FIG. 1 is a block diagram illustrating a configuration of a displaydevice according to an embodiment of the present disclosure.

Referring to FIG. 1, the display device 100 may include a broadcastreception unit 130, an external device interface unit 135, a memory 140,a user input interface unit 150, a controller 170, a short-rangecommunication unit 173, a display unit 180, an audio output unit 185,and a power supply unit 190.

The broadcast reception unit 130 may include a tuner 131, a demodulationunit 132, and a network interface unit 133.

The tuner 131 may select a specific broadcast channel according to achannel selection command. The tuner 131 may receive broadcast signalsfor the selected specific broadcast channel.

The demodulation unit 132 may divide the received broadcast signals intovideo signals, audio signals, and broadcast program related data signalsand restore the divided video signals, audio signals, and data signalsto an output available form.

The external device interface unit 135 may receive an application or anapplication list of an adjacent external device and transfer theapplication or the application list to the controller 170 or the memory140.

The external device interface unit 135 may provide a connection pathbetween the display device 100 and the external device. The externaldevice interface unit 135 may receive an image and/or an audio outputtedfrom the external device and transfers the image and/or the audio to thecontroller 170. The external device connectable to the external deviceinterface unit 135 may be one of a set-top box, a Blu-ray player, a DVDplayer, a game console, a sound bar, a smartphone, a PC, a USB memory,and a home theater system.

The network interface unit 133 may provide an interface for connectingthe display device 100 to a wired/wireless network including an Internetnetwork. The network interface unit 133 may transmit or receive data toor from another user or another electronic device through an accessednetwork or another network linked to the accessed network.

Additionally, the network interface unit 133 may transmit a part ofcontent data stored in the display device 100 to a user or an electronicdevice selected from other users or other electronic devicespreregistered in the display device 100.

The network interface unit 133 may access a predetermined webpagethrough the accessed network or another network linked to the accessednetwork. That is, the network interface unit 133 may access thepredetermined webpage through the network and transmit or receive datato or from a corresponding server.

The network interface unit 133 may receive content or data provided by acontent provider or a network operator. That is, the network interfaceunit 133 may receive content (e.g., movies, advertisements, games, VOD,broadcast signals, etc.) and content-related information provided fromthe content provider or the network operator through the network.

Additionally, the network interface unit 133 may receive updateinformation and update files of firmware provided by the networkoperator and may transmit data to the Internet or content provider orthe network operator.

The network interface unit 133 may select and receive a desiredapplication among applications, which are open to the public, throughthe network.

The memory 140 may store a program for signal processing and control inthe controller 170 and may store signal-processed image, voice, or datasignals.

Additionally, the memory 140 may perform a function for temporarilystoring image, voice, or data signals inputted from the external deviceinterface unit 135 or the network interface unit 133 and may storeinformation on a predetermined image through a channel memory function.

The memory 140 may store an application or an application list inputtedfrom the external device interface unit 135 or the network interfaceunit 133.

The display device 100 may reproduce content files (e.g., moving imagefiles, still image files, music files, document files, applicationfiles, etc.) stored in the memory 140 so as to provide the content filesto the user.

The user input interface unit 150 may transfer signals inputted by theuser to the controller 170 or may transfer signals from the controller170 to the user. For example, the user input interface unit 150 mayreceive and process control signals such as power on/off, channelselection, or screen setup from the remote control device 200 or maytransmit control signals from the controller 170 to a remote controldevice 200, according to various communication methods such asBluetooth, Ultra Wideband (WB), ZigBee, Radio Frequency (RF)communication scheme, or infrared (IR) communication scheme.

Additionally, the user input interface unit 150 may transfer, to thecontroller 170, control signals inputted from local keys (not shown)such as a power key, a channel key, a volume key, and a setting key.

Image signals that are image-processed by the controller 170 may beinputted to the display unit 180 and displayed as an image correspondingto the image signals. Additionally, image signals that areimage-processed by the controller 170 may be inputted to an externaloutput device through the external device interface unit 135.

Voice signals that are processed by the controller 170 may be outputtedas audio to the audio output unit 185. Additionally, image signals thatare processed by the controller 170 may be inputted to an externaloutput device through the external device interface unit 135.

In addition, the controller 170 may control an overall operation of thedisplay device 100.

Additionally, the controller 170 may control the display device 100 by auser command inputted through the user input interface unit 150 or aninternal program and may connect to the network to download anapplication or an application list desired by the user into the displaydevice 100.

The controller 170 may output channel information selected by the userthrough the display unit 180 or the audio output unit 185 together withthe processed image or voice signals.

Additionally, the controller 170 may output the image signal or thevoice signal, which is inputted from the external device (e.g., a cameraor a camcorder) through the external device interface unit 135, to thedisplay unit 180 or the audio output unit 185 according to an externaldevice image reproduction command received through the user inputinterface unit 150.

On the other hand, the controller 170 may control the display unit 180to display images. For example, the controller 170 may control thedisplay unit 180 to display broadcast images inputted through the tuner131, external input images inputted through the external deviceinterface unit 135, images inputted through the network interface unit,or images stored in the memory 140. In this case, an image displayed onthe display unit 180 may be a still image or video, and may be a 2Dimage or a 3D image.

Additionally, the controller 170 may perform control to reproducecontent stored in the display device 100, received broadcast content, orexternal input content inputted from the outside. The content may bevarious types, such as a broadcast image, an external input image, anaudio file, a still image, a connected web screen, a document file, andthe like.

The short-range communication unit 173 may perform a wired or wirelesscommunication with an external device. The short-range communicationunit 173 may perform short-range communication with an external device.To this end, the short-range communication unit 173 can supportshort-range communication by using at least one of Bluetooth™, RadioFrequency Identification (RFID), Infrared Data Association (IrDA), UltraWideband (UWB), ZigBee, Near Field Communication (NFC),Wireless-Fidelity (Wi-Fi), Wi-Fi Direct, and Wireless Universal SerialBus (USB) technologies. The short-range communication unit 173 maysupport wireless communication between the display device 100 and awireless communication system, between the display device 100 andanother display device 100, or between networks including the displaydevice 100 and another display device 100 (or an external server)through wireless area networks. The wireless area networks may bewireless personal area networks.

Herein, the other display device 100 may be a mobile terminal such as awearable device (for example, a smart watch, a smart glass, and a headmounted display (HMD)) or a smartphone, which is capable of exchangingdata (or interworking) with the display device 100. The short-rangecommunication unit 173 can detect (or recognize) a communicable wearabledevice around the display device 100. Furthermore, if the detectedwearable device is a device authenticated to communicate with thedisplay device 100 according to the present disclosure, the controller170 may transmit at least part of data processed by the display device100 to the wearable device through the short-range communication unit173. Accordingly, a user of the wearable device may use the dataprocessed by the display device 100 through the wearable device.

The display unit 180 may generate a driving signal by converting animage signal, a data signal, or an OSD signal, which is processed by thecontroller 170, or an image signal or a data signal, which is receivedby the external device interface unit 135, into R, G, and B signals.

On the other hand, the display device 100 shown in FIG. 1 is merely oneembodiment of the present disclosure, and some of the illustratedelements may be integrated, added, or omitted according to thespecification of the display device 100 to be actually implemented.

That is, if necessary, two or more elements may be integrated into oneelement, or one element may be divided into two or more elements.Additionally, the function performed by each block is provided fordescribing the embodiments of the present disclosure, and a specificoperation or device thereof does not limit the scope of the presentdisclosure.

According to another embodiment of the present disclosure, the displaydevice 100 may not include the tuner 131 and the demodulation unit 132,unlike that shown in FIG. 1, and may receive an image through thenetwork interface unit 133 or the external device interface unit 135 andreproduce the received image.

For example, the display device 100 may be divided into an imageprocessing device such as a set-top box for receiving a broadcast signalor content provided by various network services, and a contentreproduction device for reproducing content inputted from the imageprocessing device.

In this case, an operating method of the display device according to anembodiment of the present disclosure, which will be described below, maybe performed by the display device 100 described above with reference toFIG. 1, or may be performed by any one of the image processing devicesuch as the set-top box and the content reproduction device includingthe display unit 180 and the audio output unit 185.

Next, the remote control device according to an embodiment of thepresent disclosure will be described with reference to FIGS. 2 and 3.

FIG. 2 is a block diagram of the remote control device 200 according toan embodiment of the present disclosure, and FIG. 3 illustrates anactual configuration example of the remote control device 200 accordingto an embodiment of the present disclosure.

First, referring to FIG. 2, the remote control device 200 may include afingerprint recognition unit 210, a wireless communication unit 220, auser input unit 230, a sensor unit 240, an output unit 250, a powersupply unit 260, a memory 270, a controller 280, and a voice acquisitionunit 290.

Referring to FIG. 2, the wireless communication unit 220 transmits andreceives a signal to and from any one of the display devices accordingto the aforementioned embodiments of the present disclosure.

The remote control device 200 may include an RF module 221 configured totransmit and receive a signal to and from the display device 100according to an RF communication standard, and an IR module 223configured to transmit and receive a signal to and from the displaydevice 100 according to an IR communication standard. Additionally, theremote control device 200 may include a Bluetooth module 225 configuredto transmit and receive a signal to and from the display device 100according to a Bluetooth communication standard. Additionally, theremote control device 200 may include a Near Field Communication (NFC)module 227 configured to transmit and receive a signal to and from thedisplay device 100 according to an NFC communication standard, and aWireless LAN (WLAN) module 229 configured to transmit and receive asignal to and from the display device 100 according to a WLANcommunication standard.

Additionally, the remote control device 200 may transmit signalscontaining information on a movement of the remote control device 200 tothe display device 100 through the wireless communication unit 220.

On the other hand, the remote control device 200 may receive a signaltransmitted by the display device 100 through the RF module 221 and, ifnecessary, may transmit a command for power on/off, channel change,volume change, or the like to the display device 100 through the IRmodule 223.

The user input unit 230 may include a keypad, a button, a touch pad, ora touch screen. The user may operate the user input unit 230 to input acommand associated with the display device 100 to the remote controldevice 200. When the user input unit 230 includes a hard key button, theuser may push the hard key button to input a command associated with thedisplay device 100 to the remote control device 200. This will bedescribed below with reference to FIG. 3.

Referring to FIG. 3, the remote control device 200 may include aplurality of buttons. The plurality of buttons may include a fingerprintrecognition button 212, a power button 231, a home button 232, a livebutton 233, an external input button 234, a volume control button 235, avoice recognition button 236, a channel change button 237, a checkbutton 238, and a back button 239.

The fingerprint recognition button 212 may be a button for recognizing auser's fingerprint. According to an embodiment, the fingerprintrecognition button 212 may perform a push operation and receive a pushoperation and a fingerprint recognition operation. The power button 231may be a button for turning on or off the power of the display device100. The home button 232 may be a button for moving to a home screen ofthe display device 100. The live button 233 may be a button fordisplaying a broadcast program in real time. The external input button234 may be a button for receiving an external input connected to thedisplay device 100. The volume control button 235 may be a button foradjusting a volume outputted from the display device 100. The voicerecognition button 236 may be a button for receiving a voice of a userand recognizing the received voice. The channel change button 237 may bea button for receiving a broadcast signal of a specific broadcastchannel. The check button 238 may be a button for selecting a specificfunction, and the back button 239 may be a button for returning to aprevious screen.

Again, FIG. 2 is described.

If the user input unit 230 includes a touch screen, a user can touch asoft key of the touch screen to input a command associated with thedisplay device 100 to the remote control device 200. Additionally, theuser input unit 230 may include various types of input units operated bya user, for example, a scroll key or a jog key, and this embodiment doesnot limit the scope of the present disclosure.

The sensor unit 240 may include a gyro sensor 241 or an accelerationsensor 243, and the gyro sensor 241 may sense information on themovement of the remote control device 200.

For example, the gyro sensor 241 may sense information on the operationof the remote control device 200 on the basis of x, y, and z axes, andthe acceleration sensor 243 may sense information on a movement speed ofthe remote control device 200. Moreover, the remote control device 200may further include a distance measurement sensor and sense a distancefrom the remote control device 200 to the display unit 180 of thedisplay device 100.

The output unit 250 may output image or voice signals in response tooperation of the user input unit 230 or image or voice signalscorresponding to signals transmitted from the display device 100. A usercan recognize whether the user input unit 230 is operated or the displaydevice 100 is controlled through the output unit 250.

For example, the output unit 250 may include an LED module 251 forflashing, a vibration module 253 for generating a vibration, a soundoutput module 255 for outputting a sound, or a display module 257 foroutputting an image, if the user input unit 230 is operated or signalsare transmitted and received to and from the display device 100 throughthe wireless communication unit 220.

Additionally, the power supply unit 260 supplies power to the remotecontrol device 200 and, if the remote control device 200 does not moveduring a predetermined period of time, stops supplying power, so thatpower waste can be reduced. The power supply unit 260 may resume thesupply of power if a predetermined key provided in the remote controldevice 200 is operated.

The memory 270 may store various types of programs and application datanecessary for the control or operation of the remote control device 200.If the remote control device 200 transmits and receives signalswirelessly through the display device 100 and the RF module 221, theremote control device 200 and the display device 100 transmit andreceive signals through a predetermined frequency band.

The controller 280 of the remote control device 200 may store, in thememory 270, information on a frequency band for transmitting andreceiving signals wirelessly to and from the display device 100 pairedwith the remote control device 200 and refer to the information.

The controller 280 controls the overall operation of the remote controldevice 200. The controller 280 may transmit a signal corresponding to apredetermined key operation of the user input unit 230 or a signalcorresponding to a movement of the remote control device 200 sensed bythe sensor unit 240 to the display device 100 through the wirelesscommunication unit 220.

Additionally, the voice acquisition unit 290 of the remote controldevice 200 may obtain a voice.

The voice acquisition unit 290 may include at least one microphone 291and acquire a voice through the microphone 291.

Next, FIG. 4 is described.

FIG. 4 illustrates an example of utilizing the remote control deviceaccording to an embodiment of the present disclosure.

FIG. 4A illustrates an example in which a pointer 205 corresponding tothe remote control device 200 is displayed on the display unit 180.

A user can move or rotate the remote control device 200 vertically orhorizontally. The pointer 205 displayed on the display unit 180 of thedisplay device 100 corresponds to the movement of the remote controldevice 200. Since the pointer 205 is moved and displayed according to amovement on a 3D space as shown in the drawing, the remote controldevice 200 may also be referred to as a spatial remote control device.

FIG. 4B illustrates an example in which if a user moves the remotecontrol device 200 to the left, the pointer 205 displayed on the displayunit 180 of the display device 100 is also moved to the left accordingto the movement of the remote control device 200.

Information on the movement of the remote control device 200 detectedthrough a sensor of the remote control device 200 is transmitted to thedisplay device 100. The display device 100 may calculate the coordinatesof the pointer 205 from the information on the movement of the remotecontrol device 200. The display device 100 may display the pointer 205at a position corresponding to the calculated coordinates.

FIG. 4C illustrates an example in which while a specific button in theremote control device 200 is pressed, a user moves the remote controldevice 200 away from the display unit 180. Due to this, a selection areain the display unit 180 corresponding to the pointer 205 may be zoomedin and displayed larger.

On the contrary, if a user moves the remote control device 200 in adirection closer to the display unit 180, a selection area in thedisplay unit 180 corresponding to the pointer 205 may be zoomed out anddisplayed in a reduced size.

On the other hand, if the remote control device 200 is moved away fromthe display unit 180, a selection area may be zoomed out, and if theremote control device 200 is moved closer to the display unit 180, aselection area may be zoomed in.

Additionally, if a specific button in the remote control device 200 ispressed, recognition of a vertical or horizontal movement may beexcluded. That is, if the remote control device 200 is moved away fromor closer to the display unit 180, the up, down, left, or right movementmay not be recognized and only the back and forth movement may berecognized. While a specific button in the remote control device 200 isnot pressed, only the pointer 205 is moved according to the up, down,left, or right movement of the remote control device 200.

The moving speed or moving direction of the pointer 205 may correspondto the moving speed or moving direction of the remote control device200.

On the other hand, the pointer 205 in this specification means an objectdisplayed on the display unit 180 in response to the operation of theremote control device 200. Accordingly, besides an arrow form displayedas the pointer 205 in the drawing, various forms of objects arepossible. For example, the above concept includes a point, a cursor, aprompt, and a thick outline. The pointer 205 may be displayedcorresponding to one point of a horizontal axis and a vertical axis onthe display unit 180 and can also be displayed corresponding to aplurality of points such as a line and a surface.

Next, a driving principle of an OLED will be described with reference toFIG. 5.

FIG. 5 is a view for describing a driving principle of an OLED includedin an OLED display device according to the present disclosure.

An OLED has a structure in which a transparent indium tin oxide (ITO)anode layer is formed on a transparent substrate such as glass, and amulti-layered thin film of organic materials having different transportcapabilities and a cathode of an Mg—Ag alloy are sequentially formed onthe anode layer.

The anode layer includes an anode and a cathode, and the anode layerincludes a transparent electrode, such as ITO, so that light generatedin an emitting layer is transmitted toward the outside. Since the OLEDis a charge injection type light emitting device, charge injectionefficiency between interfaces is a factor that has the greatestinfluence on the performance of the device.

The emitting layer (EML) is a layer in which holes (+) passing throughthe anode and electrons (−) passing through the cathode recombine togenerate light.

Specifically, in the OLED, as a voltage is applied between twoelectrodes, holes and electrons are injected from the anode and thecathode, respectively, and when the holes and the electrons reach theemitting layer, the holes and the electrons recombine in the emittinglayer to form excitons of an excited state. Light is obtained byemission recombination of the excitons and becomes a ground state. Atthis time, an emission wavelength is determined by energy of exciton,that is, an energy difference between HOMO and LUMO, and the generatedlight is emitted toward the transparent electrode (anode). The lightgenerated in the emitting layer emits red, blue, and green colors, and aspectrum thereof is determined according to bond energy in the emittinglayer. Therefore, an emission color is determined according to amaterial for forming the emitting layer.

Additionally, the OLED further includes a hole injection layer (HIL), ahole transfer layer (HTL), and an electron transfer layer (ETL), whichenable the holes and the electrons to be easily moved to the emittinglayer.

The hole transfer layer uses an electron donating molecule having smallionization potential so as to facilitate hole injection from the anode.Diamine, triamine, or tetramine derivatives having triphenylamine as abasic are mainly used.

The electron transfer layer is a layer that smoothly transfers electronssupplied from the cathode to the emitting layer and suppresses themovement of holes not bonded in the emitting layer, thereby increasingrecombination probability in the emitting layer. The electron transferlayer is required to have excellent electron affinity and adhesion tothe cathode electrode.

Next, the operation of a pixel circuit, to which the OLED is connected,will be described with reference to FIG. 6.

FIG. 6 is an equivalent circuit diagram of a pixel to which the OLED ofFIG. 5 is connected, according to an embodiment.

The pixel of the OLED display device generally includes two transistorsand one capacitor (2T1C). Specifically, referring to FIG. 6, the pixelof the OLED display device includes a data line and a gate lineintersecting with each other, a switch TFT SW, a drive TFT DR, and astorage capacitor Cst.

The switch TFT SW is turned on in response to a scan pulse from the gateline so that a current path is formed between a source electrode and adrain electrode thereof. During on-time duration of the switch TFT SW, adata voltage from the data line is applied to a gate electrode of thedrive TFT DR and one electrode of the storage capacitor Cst through thesource electrode and the drain electrode of the switch TFT SW.

The storage capacitor Cst stores a difference voltage between the datavoltage and a high-potential driving voltage VDD and constantlymaintains the difference voltage during one frame period, and the driveTFT DR controls a current IOLED flowing through the OLED according tothe data voltage applied to the gate electrode thereof.

The source-drain voltage of the TFT is determined by the driving voltageVDD applied to the OLED.

FIG. 7 is a view illustrating a screen mirroring function between theOLED display device and the terminal.

Referring to FIG. 7, an OLED display device 100 (hereinafter, referredto as “display device”) may be connected with a terminal 300. Forexample, the display device 100 may be connected with the terminal 300through a communication unit which supports various well-known wirelesscommunication manners, such as Wi-Fi, Wi-Fi Direct, WLAN, or the like,or wired communication manners. The communication unit may refer to thenetwork interface unit 133 or the external device interface unit 135illustrated in FIG. 1 or may include an additional communication module.

The terminal 300 may include various mobile terminals such as asmartphone, a tablet PC, a wearable device, or the like.

For example, the user may be connected with the display device 100 andthe terminal 300 for executing the screen mirroring function. When thescreen mirroring function is executed, the terminal 300 may transmitmirroring image data, which corresponds to a screen 320 displayed on thedisplay unit of the terminal 300, to the display device 100.

The display device 100 may display a mirroring image 720 on a displayunit 180, based on the mirroring image data received from the terminal300. The mirroring image 720 may correspond to the screen 320 displayedon the display unit of the terminal 300. According to an embodiment, thedisplay device 100 may display a menu 730, which is related with thescreen mirroring function, adjacent to one side (top side) of themirroring image 720.

As illustrated in FIG. 7, the display device 100 may be in a state ofdisplaying the broadcast image 710 received from the broadcast receptionunit 130 when executing the screen mirroring function. In this case, thedisplay device 100 may display the broadcast image 710 and the mirroringimage 720 on the display unit 180. For example, the display device 100may display the broadcast image 710 and the mirroring image 720 on thedisplay unit 180 by overlaying the mirroring image 720 with a partialregion of the broadcast image 710, or by partitioning the broadcastimage 710 and the mirroring image 720 into each other.

In general, the display device 100 may display the mirroring image 720on a predetermined region of the display unit 180 without changing aregion in which the mirroring image 720 is displayed. The mirroringimage 720 may have a higher frequency in including a still image, ascompared with the broadcast image 710. In this case, since the OLEDelement corresponding to the higher brightness region of the mirroringimage 720 continuously emits higher-brightness light, the OLED elementmay have a lifespan reduced more rapidly than an OLED element providedin another region. When the lifespan of the element corresponding to thehigher brightness region is reduced, the brightness of light emittedfrom the element may be relatively reduced.

Accordingly, the afterimage phenomenon is generated on a screen of thedisplay device 100 due to the brighten difference from the element inanother region and thus a user may feel inconvenient in viewing an imagethrough the display device 100, thereby serving as a main cause ofdegrading the reliability of a product

In order to solve the above problems, according to various embodimentsof the present disclosure, the OLED display device will be describedwith reference to FIGS. 8 to 21.

FIG. 8 is a block diagram schematically illustrating elements for theoperation of the OLED display device according to an embodiment of thepresent disclosure.

Referring to FIG. 8, the display device 100 may include an image blender810, an image analyzing unit 870, and a scaler 830 as elementsprocessing images received from a plurality of sources such that theimages are simultaneously displayed on the display unit 180.

Although the image blender 810, the image analyzing unit 870, and thescaler 830 may be some elements included in the controller 170 of thedisplay device 100, the image blender 810, the image analyzing unit 870,and the scaler 830 may be implemented separately from the controller 170according to embodiments.

Although FIG. 8 illustrates a first image (broadcast image) and a secondimage (mirroring image) by way of images received from the sources, thefirst image may correspond to various images provided from the networkinterface 133, the external device interface unit 135, or the storageunit 140 instead of the broadcast image.

The image blender 810 may create one blending image by blending thefirst image with the second image. In detail, the image blender 810 mayarrange the frame of the first image and the frame of the second imagein one blending frame. For example, the image blender 810 may arrangethe frame of the first image in the whole region of the blending frameand arrange the frame of the second image in a partial region of theframe of the first region by overlaying the frame of the second imagewith the partial region of the frame of the first image. For example,the image blender 810 may arrange the frame of the first image in apartial region of the blending frame and arrange the frame of the secondimage in a remaining region of the blending frame which is notoverlapped with the frame of the first image.

The scaler 830 may scale the first image and the second image to haveresolutions allowing the output through the display unit 251 and maytransmit the first image and the second image to the display unit 180.The scaler 830 may include a main scaler which scales the first imageand a sub-scaler which scales the second image.

The image analyzing unit 820 may control the state of the second imagebased on an average picture level (APL) of the second image of theblending image output from the image blender 810. To this end, the imageanalyzing unit 820 may include an APL acquisition unit 821, an APLvariation calculating unit 822, and a display state control unit 823.

The APL acquisition unit 821 may acquire the APL of the second image ofthe blending image. When the first image is blended with the secondimage by the image blender 810, the region in which the second image isdisplayed may be preset. Accordingly, the APL acquisition unit 821 mayacquire the APL of the second image by acquiring the APL for the regionin which the second image of the blending image is displayed. Meanwhile,the APL may refer to an average brightness value for the specificregion.

Regarding the frame of the second image, the APL acquisition unit 821may periodically acquire the APL of the second image. In other words,the APL acquisition unit 821 may acquire the APL with respect to each ofthe frames of the second image or may acquire the APL at a predeterminedframe interval. According to the embodiment, the acquired APL may bestored in the storage unit 140.

The APL variation calculating unit 822 may calculate an APL variation bycomparing the APL, which is acquired by the APL acquisition unit 821,with a previously acquired APL.

The display state control unit 823 may detect, based on the APLvariation, whether frames of the second image are identical to eachother and may determine whether the terminal transmitting the secondimage operates depending on the detecting result. The operation of theterminal 300 may refer to that the screen displayed on the display unitof the terminal 300 by the manipulation of the user is changed as timeelapses. That the terminal 300 does not operate may refer to that thesame screen is displayed on the display unit of the terminal 300 as theuser does not manipulate the terminal 300. In other words, that the samescreen is displayed on the display unit as the user does not manipulatethe terminal 300 may refer to that the user does not view the screen ofthe terminal 300 and the second image displayed on the display device100.

The display state control unit 823 may detect that the frames of thesecond image are identical to each other when the APL variation is lessthan a reference variation (or equal to or less than the referencevariation). When each of APL variations continuously calculated during apredetermined time or a predetermined count is less than the referencevariation (or equal to or less than the reference variation), thedisplay state control unit 823 may determine that the terminal 300 doesnot operate. Accordingly, the display state control unit 823 maydetermine the operation state of the terminal 300 only when the acquiredAPL is higher than the reference APL. This is because, when thebrightness of the second image is lower than predetermined brightness,the difference in a lifespan reduction degree between the OLED elementsmay not be greatly represented between the region in which the secondimage is displayed and a remaining region.

The display state control unit 823 may control the image blender 810 orthe scaler 830 such that the display state of the second image ischanged, when each of the APL variations continuously calculated duringthe predetermined time or a predetermined count is less than thereference variation (or equal to or less than the reference variation).

For example, the display state control unit 823 may control the imageblender 810 or the scaler 830 such that the second image is notdisplayed on the display unit 180. According to an embodiment, thedisplay state control unit 823 may control the image blender 810 or thescaler 830 by adjusting the transparency of the second image oradjusting the size of the second image as a time or a count to maintainthat the APL variation is less than the reference variation. In thisconnection, the image blender 810 may include an alpha blender foradjusting the transparency of the second image. The alpha blender maysynthesize the second image with the first image by employing thetransparency of the second image. Accordingly, the overlap between thefirst image and the second image may be displayed on the region in whichthe second image is displayed. For example, as the transparency isincreased, the second image may be more transparent and the first imagemay more become sharpened.

Meanwhile, the display state control unit 823 may control the imageblender 810 and the scaler 830 such that the display of the second imageis maintained when the calculated APL variation is equal to or greaterthan the reference variation (or excesses the reference variation).Accordingly, the second image may be continuously displayed in thepreset region.

Hereinafter, the operations of the OLED display device according tovarious embodiments of the present disclosure will be described withreference to FIGS. 9 to 21.

FIG. 9 is a flowchart illustrating the operation of controlling thedisplay state of the mirroring image by the OLED display deviceaccording to an embodiment of the present disclosure.

Referring to FIG. 9, the display device 100 may be connected with theterminal 300 to execute a screen mirroring function (S100).

For example, the user may connect the display device 100 with theterminal 300 through a predetermined communication manner and mayexecute the screen mirroring function to display the image correspondingto the screen of the terminal 300 on the display unit 180.

The display device 100 may display a mirroring image on the display unit180 based on the mirroring image data received from the terminal 300 asthe screen mirroring function is executed (S110).

As described above, the controller 170 may display the mirroring image,which is based on mirroring image data received from the terminal 300,on a predetermined region of the display unit 180. According to anembodiment, when the display device 100 displays another image of abroadcast image, the controller 170 may display the mirroring image byoverlaying the mirroring image with a specific region of the anotherimage or by partitioning the another image and the mirroring image intoeach other.

The display device 100 may calculate the APL variation by periodicallyacquiring the APL of the mirroring image (S120).

In detail, the controller 170 may acquire the APL of the mirroring imagefrom the received mirroring image data with respect to each frame or ata predetermined frame interval and may calculate the APL variation bycomparing the acquired APL with the previously-acquired APL. Accordingto the embodiment, the controller 170 may aperiodically acquire the APLof the mirroring image.

The display device 100 may control the display state of the mirroringimage based on the calculated APL variation (S130).

Steps S120 and S130 will be described in more detail with reference toFIG. 10.

FIG. 10 is a flowchart illustrating an operation of the OLED displaydevice illustrated in FIG. 9 in more detail.

Referring to FIG. 10, the display device 100 may acquire the APL of themirroring image (S121).

For example, the controller 170 may acquire the APL for a present framefrom the mirroring image data received from the terminal 300.

The display device 100 may calculate the APL variation between theacquired APL and a previously acquired APL (S122).

The controller 170 may calculate the APL variation by comparing theacquired APL for the present frame with an APL acquired for a previousframe or frames before the predetermined number of frames.

The display device 100 may determine the mirroring image as beingidentical and may increase a count when the calculated APL variation isless than the reference variation (or equal to or less than thereference variation (see Yes of S123)).

Meanwhile, the display device 100 may increase a count when the APLvariation is less than the reference variation and when the APL acquiredin S121 is higher than the reference APL (or equal to or higher than thereference APL). In addition, according to the embodiment, when the APLacquired in step S121 is lower than the reference APL (or equal to orlower than the reference APL), steps S122 and S123 may not be performedand the display state of the mirroring image may be maintained.

According to an embodiment, the count may refer to a time measured by atimer (not illustrated) of the display device 100. In this case, thethreshold count may refer to a preset threshold time.

When the count exceeds the preset threshold count (or arrives to thethreshold count) (see Yes of S125), the display device 100 may perform acontrol operation such that the mirroring image is not displayed(referred to as “non-display state”) (S131). Meanwhile, when the countis lower than the preset threshold count, steps S121 to S123 may beperformed with respect to a next frame of the mirroring image or framesafter the predetermined number of frames.

The threshold count may correspond to the reference allowing the displaydevice 100 to determine the operation state of the terminal 300 asdescribed with reference to FIG. 8. The display device 100 may determinethat the terminal 300 is not operated when the count exceeds thethreshold count.

Meanwhile, in step S123, when the APL variation is equal to or greaterthan (or exceeds) the reference variation, the display device 100 mayinitialize the count and may continuously display the mirroring image.In other words, when the APL variation is equal to or greater than thereference variation, the controller 170 may determine that the terminal300 operates and may display the mirroring image on the display unit180.

Meanwhile, in this connection with step S131, the display device 100 maychange the display state of the mirroring image according to theincrease of the count or the time for maintaining the state that the APLvariation is less than the reference variation and may change the stateof the mirroring image to the non-display state when the count or thetime exceeds the threshold count or the threshold time, respectively.Various embodiments related to this will be described with reference toFIGS. 11 to 15.

FIGS. 11 to 15 are views illustrating various embodiments related to theoperation that the OLED display device may change the state of themirroring image to the non-display state, based on embodimentsillustrated in FIGS. 9 and 10.

Referring to FIG. 11, the controller 170 may display a first image 1110and a second image 1120 on the display unit 180. It is assumed that thefirst image 1110 is a broadcast image 1110 received from the broadcastreception unit 130. The second image 1120 may be the mirroring image1120 received from the terminal 300 as the screen mirroring function isexecuted.

The controller 170 may display the broadcast image 110 on the fullregion of the display unit 180 and may display the mirroring image 1120by overlaying the mirroring image 1120 with a partial region of thebroadcast image 1120.

According to an embodiment, the controller 170 may further display amirroring menu 1130 including a menu or an icon related to the screenmirroring function. The mirroring menu 1130 may be displayed adjacent toone side (for example, an upper side) of the mirroring image 1120.

As described above with reference to FIGS. 9 and 10, the controller 170may periodically calculate an APL for the mirroring image 1120 and maychange the state of the mirroring image 1120 to the non-display statewhen the APL variation of the mirroring image 1120 is maintained to beless than the reference variation during the threshold time or thethreshold count. Accordingly, the broadcast image 1110 may be displayedon a region R in which the mirroring image 1120 is displayed. Even ifthe state of the mirroring image 1120 is changed to the non-displaystate, since the screen mirroring function is not terminated, themirroring menu 1130 may be continuously displayed.

As the state of the mirroring image 1120 is changed to the non-displaystate, a portion of the broadcast image 1110 may be displayed on theregion R in which the mirroring image 1120 is displayed. In other words,the OLED element positioned in the region R displays the broadcast image1110 having the varying APL without continuously emitting the same lightas the APL of the mirroring image 1120 is not changed for a long time,the OLED element may represent a lifespan reduction degree approximateto that of OLED element existing in another region other than the regionR. Accordingly, the afterimage phenomenon occurring in the display unit180 due to the lifespan difference may be prevented.

Meanwhile, referring to FIGS. 12A to 12C, the controller 170 may adjustthe transparency of the mirroring image 1220, based on the time or thecount for maintaining that the APL variation is less than the referencevariation.

For example, when the time that the APL variation is less than thereference variation is a first time, the controller 170 may display themirroring image 1221 having the transparency adjusted to the firsttransparency as illustrated in FIG. 12B. In addition, when the time thatthe APL variation is less than the reference variation is increased to asecond time (that is, the second time is greater than the first time),the controller 170 may display the mirroring image 1222 having thetransparency adjusted to the second transparency greater than the firsttransparency as illustrated in FIG. 12C. As the transparency isincreased, the mirroring images 1220 to 1222 are transparent and thebroadcast image 1210 in the region overlapped with the mirroring images1220 to 1222 may be cleared.

Finally, when the time that the APL variation is less than the referencevariation arrives at the threshold time, the controller 170 may does notdisplay the mirroring image as illustrated in FIG. 11.

Referring to FIG. 13, according to an embodiment, the terminal 300 maybe locked when the user does not manipulate the terminal 300 for apredetermined time. In this case, the locking screen may be displayed onthe display unit of the terminal 300. When the predetermined time isshorter than the above-described threshold time, before the controller170 changes the display state of the mirroring image to the non-displaystate, the screen of the terminal 300 may be changed to the lockingscreen.

In this case, the controller 170 may display the locking icon 1320,which represents the locking state of the terminal 300, on the displayunit 180 instead of displaying the mirroring image corresponding to thelocking screen of the terminal 300. The terminal 300 may transmit asignal for representing the change to the locking state to the displaydevice 100 in the change to the locking state. The controller 170 maysense that the terminal 300 is switched to the locking state byreceiving the signal from the terminal 300. The controller 170 maydisplay the locking icon 1320 on the display unit 180 together with thebroadcast image 1310, instead of the mirroring image transmitted fromthe terminal 300, based on the sensing result. According to anembodiment, the display position of the locking icon 1320 may beperiodically or aperiodically changed. For example, the locking icon1320 may be displayed while moving along the edge region of the displayunit 180, but the present disclosure is not limited thereto.

Referring to FIGS. 14 and 15, the controller 170 may display thebroadcast image 1410 and the mirroring image 1420 on the full region ofthe display unit 180 by partitioning the broadcast image 1410 and themirroring image 1420 into each other. For example, the broadcast image1410 may be displayed on the first region of the display unit 180 andthe mirroring image 1420 may be displayed on the second region of thedisplay unit 180. The second region may correspond to the region thatdoes not overlap with the first region. In this case, as illustrated indrawings, the image may be not displayed on a partial region of thedisplay unit 180 due to the ratio between the broadcast image 1410 andthe mirroring image 1420. As the broadcast image 1410 and the mirroringimage 1420 are partitioned into each other and displayed, the size ofthe broadcast image 1410 may be reduced as compared with the size of thebroadcast image 1110 illustrated in FIG. 11.

The controller 170 may change the state of the mirroring image 1420 tothe non-display state as illustrated in FIG. 14 and may display a screenprotection image 1421 on the region that the mirroring image 1420 isdisplayed when a time or a count for maintaining the display state thatthe APL variation of the mirroring image 1420 is less than the referencevariation arrives at a threshold time or a threshold count. The screenprotection image 1421 may correspond to a moving picture instead of astill image.

Referring to FIGS. 15A to 15C, the controller 170 may adjust the size ofthe mirroring image 1520 according to the increase of the time or thecount for maintaining the display state that the APL variation of themirroring image 1520 is less than the reference variation.

For example, the controller 170 may display the mirroring image 1521having a size adjusted to the first size as illustrated in FIG. 15B,when a time for maintaining the state that the APL variation is lessthan the reference variation is the first time. In addition, thecontroller 170 may display the mirroring image 1522 having the sizeadjusted to the second size less than the first size as illustrated inFIG. 15C when the time that the APL variation is less than the referencevariation is increased to the second time (in other words, the secondtime is greater than the first time). As the sizes of the mirroringimages 1520 to 1522 are reduced, the size of the broadcast image 1510may be increased.

Finally, when the time for maintaining that the APL variation is lessthan the reference variation arrives at the threshold time, thecontroller 170 may not display the mirroring image and may display thebroadcast image 1510 on the full region 1500 of the display unit 180.

In other words, according to an embodiment of the present disclosure,the display device 100 may change the state of the mirroring image tothe non-display state when the APL of the mirroring image is not changedfor a predetermined time. Accordingly, since the OLED elementspositioned in the region, in which the mirroring image is displayed, maydisplay the broadcast image having the varied APL instead ofcontinuously emitting the same as the APL of the mirroring image is notchanged for a long time, the OLED elements may have a lifespan reductiondegree approximate to that of the OLED elements present in anotherregion. Accordingly, the afterimage phenomenon occurring on the displayunit 180 due to the lifespan difference between OLED elements may beprevented.

FIGS. 16 and 17 are flowcharts illustrating embodiments of an operationthat the OLED display device changes the non-display state of themirroring image according to the embodiments of FIGS. 10 to 15 to thedisplay state.

Referring to FIG. 16, the display device 100 may acquire the APL of amirroring image received from the terminal 300 (S1600).

In other words, even when the state of the mirroring image is thenon-display state, the screen mirroring function is not terminated.Accordingly, the display device 100 may continuously receive themirroring data from the terminal 300. The controller 170 may acquire theAPL of the mirroring image based on the received mirroring image data(for example, may acquire the APL at a predetermined interval).

The display device 100 may calculate an APL variation between theacquired APL and the previously-acquired APL (S1610), and may perform acontrol operation such that the mirroring image is displayed (S1630)when the calculated APL variation exceeds the reference variation (or isequal to or greater than the reference variation) (see YES of S1620).

For example, when the user may operate the terminal 300 or when an eventoccurs in the terminal 300, the screen of the terminal 300 may bechanged. In this case, the APL of the mirroring image may be varied andthe controller 170 may change the non-display state of the mirroringimage to the display state in response to the variation in the APL.

Referring to FIG. 17, the terminal 300 may be switched to a sleep statewhen there is absent the operation of the terminal 300 by the user orwhen the event does not occur for a predetermined time (S1700). Thesleep state may refer to the state that the terminal 300 may nottransmit the mirroring image data to the display device 100 or may notperform other functions.

When a specific event occurs in the sleep state, the terminal 300 may beswitched to a wake-up state (S1710). For example, the terminal 300 inthe sleep state may be switched to the wake-up state due to user inputor other events.

As the terminal 300 is switched to the wake-up state, the terminal 300may transmit the wake-up signal to the display device 100 (S1720). Thedisplay device 100 may perform a control operation such that themirroring image is displayed, in response to the wake-up signal (S1730).

That the terminal 300 is switched to the wake-up state may refer to thatthe terminal 300 performs a specific operation. In this case, thedisplay device 100 may determine that the terminal 300 operates and thusmay change the mirroring image from the non-display state to the displaystate.

In other words, the display device 100 may display the mirroring imageon the display unit 180 in response to the wake-up signal received fromthe terminal 300 as the state of the terminal 300 is changed.

FIGS. 18 and 19 are views related to the operation of the OLED displaydevice illustrated in FIGS. 16 to 17.

Referring to FIG. 18, the display device 100 may continuously receivethe mirroring image data corresponding to the screen 340 which is beingdisplayed on the terminal 300 from the terminal 300 when the screenmirroring function is not terminated as if the mirroring image is in thenon-display state. The controller 170 may display a portion of thebroadcast image 1810 without displaying the mirroring mage on the regionR in which the mirroring image is displayed, since the mirroring imageis in the non-display state.

Referring to FIG. 19, the user may execute a specific application (e.g.,a gallery application) by operating the terminal 300. As the terminal300 executes the specific application, the screen 342 displayed on theterminal 300 may be changed.

In this case, the mirroring image data transmitted by the terminal 300may be changed. The controller 170 of the display device 100 may acquirean APL from the received mirroring image data and may compare theacquired APL with the previously-acquired APL. In this case, the APLvariation may be higher than the reference variation, and the controller170 may change the mirroring image 1920 from the non-display state tothe display state by determining that the terminal 300 operates.Accordingly, the mirroring image 1920 may be displayed on the displayunit 180.

According to an embodiment, the terminal 300 may be changed from thesleep state to the wake-up state as a specific application is executedby the user. In this case, the terminal 300 may transmit the wake-upsignal to the display device 100. The controller 170 may change themirroring image 1920 from the non-display state to the display state inresponse to the wake-up signal received from the terminal 300 and thusmay display the mirroring image 1920 on the display unit 180.

FIG. 20 is a flowchart illustrating embodiments of an operation that theOLED display device changes the non-display state of the mirroring imageaccording to the embodiments of FIGS. 10 to 15 to the display state.FIG. 21 is a view related to the operation of the OLED display deviceillustrated in FIG. 20.

Referring to FIG. 20, the display device 100 may receive an input forselecting a mirroring menu displayed on the display unit 180 or mayreceive a request for the re-execution of a screen mirroring function(S2000). In this case, the display device 100 may perform a controloperation such that the mirroring screen is displayed (S2010).

Referring to FIG. 21A in this connection, the controller 170 of thedisplay device 100 may display the mirroring menu 2130 on the displayunit 180 when the screen mirroring function is not terminated as if themirroring image is in the non-display state.

For example, when a mirroring image, which has been displayed on thespecific region R of the display unit 180, is not displayed, the usermay control the remote control device 200 to move a pointer 205 to theregion in which a mirroring menu 2130 is displayed and to select aspecific menu icon 2131. The controller 170 may switch the mirroringimage 2120 from the non-display state to the display state asillustrated in FIG. 21B in response to the input for selecting aspecific menu icon 2131 and thus the mirroring image 2120 may bedisplayed on the display unit 180.

In other words, according to the embodiment illustrated in FIGS. 16 to21, the display device 100 may automatically change the state of themirroring image to the display state based on the APL of the mirroringimage or may change the state of the mirroring image to the displaystate through the simple manipulation of the user, thereby increasingthe convenience of the user.

According to various embodiments of the present disclosure, the OLEDdisplay device may change the state of the mirroring image to thenon-display state when the APL of the mirroring image is not changed fora predetermined time. Accordingly, since the OLED elements positioned inthe region in which the mirroring image is displayed may display thebroadcast image having a varied APL instead of continuously emitting thesame light as the mirroring image is not changed for a long time, theOLED elements may have a lifespan reduction degree approximate to thatof OLED elements present in another region. Accordingly, the afterimagephenomenon occurring on the display unit due to the lifespan differencebetween OLED elements may be prevented.

In particular, as the brightness of the mirroring image is increased,the lifespan difference between OLED elements may be increased.Accordingly, the OLED display device may change the state of themirroring image to the non-display state based on the APL variation whenthe APL of the mirroring image is equal to greater than a predeterminedlevel. Accordingly, the effect of preventing the afterimage phenomenonmay be maximized.

In addition, the OLED display device may automatically change themirroring image to the display state based on the APL of the mirroringmage or the state of the terminal or may change the state of themirroring image to the display state through the simple manipulation ofthe user. Accordingly, the convenience of the user may be increased.

According to an embodiment of the present disclosure, theabove-described method is able to be implemented with codes allowing aprocessor to be readable a medium having a program. Theprocessor-readable medium may include a ROM, a RAM, a CD-ROM, a magnetictape, a floppy disc, an optical data storage device, or the like.

The above-described display device does not limitedly employ theelements and the methods according to the above embodiments, but variousmodifications are possible and the whole embodiments or a part of theembodiments may be selectively combined with each other.

What is claimed is:
 1. An organic light emitting diode (OLED) displaydevice comprising: a communication transceiver configured to connectwith a terminal; a display including pixels constituted by OLEDs; and acontroller configured to: receive mirroring image data, whichcorresponds to a screen displayed on the terminal, through thecommunication transceiver, control the display to display a mirroringimage on an area of the display based on the received mirroring imagedata, and adjust brightness of the displayed mirroring image based on anaverage picture level (APL) of the displayed mirroring image.
 2. TheOLED display device of claim 1, wherein the controller is configured to:acquire an APL of a frame of the mirroring image from the mirroringimage data, calculate an APL variation by comparing the acquired APLwith a previously-acquired APL, and adjust the brightness of thedisplayed mirroring image, based on the calculated APL variation.
 3. TheOLED display device of claim 2, wherein the controller is configured to:maintain the brightness of the displayed mirroring image when theacquired APL is less than the reference APL, and decrease the brightnessof the displayed mirroring image, based on the APL variation when theacquired APL is equal to or greater than a reference APL.
 4. The OLEDdisplay device of claim 2, wherein the controller is configured to:acquire an APL at a predetermined frame interval of the mirroring image,and decrease the brightness of the displayed mirroring image, whenmaintaining, for a threshold time, a state that the APL variationbetween the acquired APL and the previously-acquired APL is less than areference variation.
 5. The OLED display device of claim 2, wherein thecontroller is configured to: display a broadcast image, which isreceived from a broadcast reception interface, on the display, displaythe mirroring image by overlaying the mirroring image with the area ofthe broadcast image, and adjust the brightness of the displayedmirroring image of an area where the mirroring image is displayed basedon the APL variation.
 6. The OLED display device of claim 1, wherein thecontroller is configured to: adjust the brightness by adjusting atransparency of the displayed mirroring image.
 7. The OLED displaydevice of claim 2, wherein the controller is configured to: periodicallyacquire an APL of the mirroring image, increase a count when an APLvariation between the acquired APL and the previously-acquired APL isless than a reference variation, and decrease the brightness of thedisplayed mirroring image, when the count arrives at a threshold countor exceeds the threshold count.
 8. The OLED display device of claim 1,wherein the controller is configured to: when decreasing the brightnessof the displayed mirroring image, acquire an APL of the mirroring imageat a predetermined frame interval based on the mirroring image datareceived from the terminal, and increase the brightness of the displayedmirroring image, based on an APL variation between the acquired APL andthe previously-acquired APL.
 9. The OLED display device of claim 1,wherein the controller is further configured to: when decreasing thebrightness of the displayed mirroring image, increase the brightness ofthe displayed mirroring image, in response to a wake-up signal receivedfrom the terminal as a state of the terminal is changed.
 10. The OLEDdisplay device of claim 1, wherein the controller is further configuredto: display a mirroring menu on the display, and after decreasing thebrightness of the displayed mirroring image, increase the brightness ofthe displayed mirroring image in response to a selection input of themirroring menu.
 11. A method for operating an OLED display device, themethod comprises: receiving mirroring image data, which corresponds to ascreen displayed on a terminal connected with the OLED display device,from the terminal; controlling a display included in the OLED displaydevice to display a mirroring image on an area of the display based onthe received mirroring image data; and adjusting brightness of thedisplayed mirroring image, based on an APL of the mirroring image. 12.The method of claim 11, wherein the adjusting the brightness of thedisplayed mirroring image includes: acquiring an APL of a frame of themirroring image from the mirroring image data; calculating an APLvariation by comparing the acquired APL with a previously-acquired APL;and adjusting the brightness of the displayed mirroring image, based onthe calculated APL variation.
 13. The method of claim 12, wherein theadjusting the brightness of the displayed mirroring image, based on thecalculated APL variation includes: decreasing the brightness of thedisplayed mirroring image, based on the APL variation when the acquiredAPL is equal to or greater than a reference APL; and maintaining thebrightness of the displayed mirroring image when the acquired APL isless than the reference APL.
 14. The method of claim 12, wherein theacquiring of the APL of the frame of the mirroring image includes:acquiring an APL at a predetermined frame interval of the mirroringimage, and wherein the adjusting the brightness of the displayedmirroring image, based on the calculated APL variation includes:decreasing the brightness of the displayed mirroring image, whenmaintaining, for a threshold time, a state that the APL variation isless than a reference variation.
 15. The method of claim 11, wherein theadjusting the brightness of the displayed mirroring image adjusts atransparency of the displayed mirroring image, wherein the brightness ofthe displayed mirroring image increases by decreasing the transparencyof the displayed mirroring image, and wherein the brightness of thedisplayed mirroring image decreases by increasing the transparency ofthe displayed mirroring image.